# US 8,539,666 B2 · Method for making an electrical inductor and related inductor devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,539,666 B2 - Document ID: US8539666B2 - Status: Granted - Kind: B2 - Application number: 13/293,671 - Filed: 2011-11-10 - Published: 2013-05-16 - Granted: 2013-09-24 - Earliest claimed: 2011-11-10 - Assignees: Harris Corporation - Applicants: Michael Raymond Weatherspoon; Louis Joseph Rendek, Jr.; Lawrence Wayne Shacklette; Robert Patrick Maloney; David M. Smith - Inventors: Michael Raymond Weatherspoon; Louis Joseph Rendek, Jr.; Lawrence Wayne Shacklette; Robert Patrick Maloney; David M. Smith - Web page: https://patentgrep.com/patent/US8539666B2 ## CPC - H01F 27/2804: {Printed windings} - H01F 5/00: Coils (superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00) - H01F 17/0006: {Printed inductances (printed coils for dynamo-electric machines H02K3/26; printed circuits H05K)} - H01F 41/041: {Printed circuit coils (apparatus or processes for manufacturing printed circuits in general H05K3/00)} - H01F 2017/0046: {with a conductive path having a bridge} - H01F 2017/0073: {with a special conductive pattern, e.g. flat spiral} - H05K 1/165: {incorporating printed inductors} - H05K 3/146: {By vapour deposition} - H05K 3/16: by cathodic sputtering - H05K 3/20: by affixing prefabricated conductor pattern {(H05K1/187, H05K3/046, H05K3/4658, H05K3/4682 takes precedence)} - H05K 2201/0141: Liquid crystal polymer [LCP] - H05K 2201/0305: Solder used for other purposes than connections between PCB or components, e.g. for filling vias or for programmable patterns - H05K 2201/1003: Non-printed inductor - H05K 2203/016: Temporary inorganic, non-metallic carrier, e.g. for processing or transferring - Y10T 29/4902: Electromagnet, transformer or inductor - Y10T 29/49071: by winding or coiling - Y10T 29/49073: by assembling coil and core - Y10T 29/49075: including permanent magnet or core - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method is for making an electrical inductor. The method includes forming a first subunit having a sacrificial substrate, and an electrically conductive layer defining the electrical inductor and including a first metal on the sacrificial substrate. The method includes forming a second subunit having a dielectric layer and an electrically conductive layer thereon defining electrical inductor terminals and having the first metal, and coating a second metal onto the first metal of one of the first and second subunits. The method includes aligning the first and second subunits together, heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals bonding adjacent metal portions together, and removing the sacrificial substrate. ## Claims ### Claim 1 A method of making an electrical inductor comprising: forming a first subunit comprising a sacrificial substrate, and an electrically conductive layer defining the electrical inductor and comprising a first metal on the sacrificial substrate; forming a second subunit comprising a dielectric layer and an electrically conductive layer on the dielectric layer, the electrically conductive layer defining electrical inductor terminals and comprising the first metal; coating a second metal onto the first metal of at least one of the first and second subunits; selecting the first metal to have a melting point temperature greater than that of the second metal, and selecting the second metal to have a melting point temperature below a lamination temperature of the dielectric layer; aligning the first and second subunits together; heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals by bonding adjacent metal portions of the first and second metals together; and removing the sacrificial substrate. ### Claim 2 (depends on 1) The method of claim 1 further comprising selecting the dielectric layer of the second subunit to comprise a liquid crystal polymer (LCP) layer. ### Claim 3 (depends on 1) The method of claim 1 further comprising forming the electrically conductive layer on the first subunit to define the electrical inductor having a plurality of turns. ### Claim 4 (depends on 1) The method of claim 1 further comprising selecting the first metal to comprise copper, and selecting the second metal to comprise tin. ### Claim 5 (depends on 1) The method of claim 1 further comprising selecting the sacrificial substrate to comprise a glass substrate. ### Claim 6 (depends on 1) The method of claim 1 wherein removing the sacrificial substrate comprises using an etching solution. ### Claim 7 (depends on 1) The method of claim 1 wherein removing the sacrificial substrate comprises using a polishing process. ### Claim 8 (depends on 1) The method of claim 1 wherein removing the sacrificial substrate comprises plasma etching the sacrificial substrate. ### Claim 9 (depends on 1) The method of claim 1 wherein forming the first subunit comprises forming the first subunit to include a release layer between the sacrificial substrate and the electrically conductive layer. ### Claim 10 (depends on 1) The method of claim 1 wherein forming the second subunit comprises forming the second subunit to include a circuit on the dielectric layer and coupled to the electrically conductive layer. ### Claim 11 A method of making an electrical inductor comprising: forming a first subunit comprising a sacrificial substrate, and an electrically conductive layer defining the electrical inductor and comprising a first metal on the sacrificial substrate; forming a second subunit comprising a liquid crystal polymer (LCP) dielectric layer and an electrically conductive layer on the LCP dielectric layer, the electrically conductive layer defining electrical inductor terminals and comprising the first metal; selecting the first metal to have a melting point temperature greater than that of a second metal, and selecting the second metal to have a melting point temperature below a lamination temperature of the LCP dielectric layer; coating the second metal onto the first metal of at least one of the first and second subunits; aligning the first and second subunits together; heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals by bonding adjacent metal portions of the first and second metals together; and removing the sacrificial substrate. ### Claim 12 (depends on 11) The method of claim 11 further comprising forming the electrically conductive layer on the first subunit to define the electrical inductor having a plurality of turns. ### Claim 13 (depends on 11) The method of claim 11 further comprising selecting the sacrificial substrate to comprise a glass substrate. ### Claim 14 (depends on 11) The method of claim 11 wherein removing the sacrificial substrate comprises using an etching solution. ### Claim 15 (depends on 11) The method of claim 11 wherein removing the sacrificial substrate comprises using a polishing process. ### Claim 16 (depends on 11) The method of claim 11 wherein removing the sacrificial substrate comprises plasma etching the sacrificial substrate. ### Claim 17 A method of making an electrical inductor comprising: forming a first subunit comprising a sacrificial substrate, and an electrically conductive layer defining the electrical inductor and comprising a first metal on the sacrificial substrate; forming a second subunit comprising a liquid crystal polymer (LCP) dielectric layer and an electrically conductive layer on the LCP dielectric layer, the electrically conductive layer defining electrical inductor terminals and comprising the first metal; coating a second metal onto the first metal of at least one of the first and second subunits; aligning the first and second subunits together; heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals bonding adjacent metal portions together; and removing the sacrificial substrate. ### Claim 18 A method of making an electrical inductor comprising: forming a first subunit comprising a sacrificial substrate, an electrically conductive layer defining the electrical inductor and comprising a first metal on the sacrificial substrate, and a release layer between the sacrificial substrate and the electrically conductive layer; forming a second subunit comprising a dielectric layer and an electrically conductive layer on the dielectric layer, the electrically conductive layer defining electrical inductor terminals and comprising the first metal; coating a second metal onto the first metal of at least one of the first and second subunits; aligning the first and second subunits together; heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals bonding adjacent metal portions together; and removing the sacrificial substrate. ### Claim 19 A method of making an electrical inductor comprising: forming a first subunit comprising a sacrificial substrate, and an electrically conductive layer defining the electrical inductor and comprising a first metal on the sacrificial substrate; forming a second subunit comprising a dielectric layer, an electrically conductive layer on the dielectric layer, and a circuit on the dielectric layer and coupled to the electrically conductive layer, the electrically conductive layer defining electrical inductor terminals and comprising the first metal; coating a second metal onto the first metal of at least one of the first and second subunits; aligning the first and second subunits together; heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals bonding adjacent metal portions together; and removing the sacrificial substrate.